Error with Blog PHP & Symfony

<?php

namespace SoftUniBlogBundle\Controller;

use SoftUniBlogBundle\Entity\Article;
use SoftUniBlogBundle\Form\ArticleType;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Security;
use Symfony\Component\HttpFoundation\Request;

class ArticleController extends Controller
{
    /**
     * Route("/article/create", name="article_create")
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function create(Request $request)
    {
        $article = new Article();
        $form = $this->createForm(ArticleType::class, $article);
        $form->handleRequest($request);

        if ($form->isValid())
        {
            $article->setAuthor($this->getUser());
            $em = $this->getDoctrine()->getManager();
            $em->persist($article);
            $em->flush();

            return $this->redirectToRoute('blog_index');
        }
        return $this->render('article/create.html.twig',
            [
                'form' => $form->createView()
            ]
        );
    }

    /**
     * @Route("/article/{id}", name="article_view")
     * @param $id
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function viewArticle($id)
    {
        $article = $this->getDoctrine()->getRepository(Article::class)->find($id);

        return $this->render('article/create.html.twig', ['article' => $article]);
    }
}